Electroplating apparatus for moving strip



Patented Sept. 9, 1952 ELECTROPLATING APPARATUS FOR MOVING STRIP Walter W.:K'ompart, Steubenville; Ohio, assign'or toNational SteelCorporation, a corporation of Delaware dri'ginalapplication May 28, 1943, serial No. 488,866. Divided and thisapplicatio'n April 18, 1950, SerialNo. 156,693

2Glaims. (clean-206.)

The present. invention relates to continuous electroplating ofua moving; strip. havingla conductiveiace.

This application is. a division: of application SerialNoi 488;866,.now abandoned, filed May 28, 1943 by myself-fand-.AbramB. Wilson. Application Serial No. 791,150, which is a. division of application. Serial No: 488-,86-6,,was filed March 2,

lii lilsbyAbramBi Wilson.

More particularly; the present invention relatest'o'electroplating of a protective metal such as tin, zinc, nickel, chromium, etc. on: a metal strip, wherein'ano'de's f the: coating metal. are supplied. with electroplating current through a connection submerged in the electrolyte;

The presentinventionis especially adapted for use in .lelectroplatings systems of the general type disclosed in copending application Serial No. 48 '7,758filedMay '20, 1943 by Ernest'W. Rieger and Clarence'J-i Klein which issued as Patent No. 2,399,254 on April"30, 1946. In electroplating systems-of-this type amovin'gstriphaving a conductive face, for examplesteelstrip, is moved through an electroplating'zone in which at least one faceof thestripis contacted'with an electrolyte; Submerged under' the surface ofthe electrolyte andin electrolytic relation with the iace f the strip are-anodes ofthe metal to'be plated on the strip. These anodes may be arranged in any desirable manner to give'a uniform coating action, but normally they are movably supported on anode supports from at least one of which they collect electroplating current. Since-the connection between these anodes. and the support which carries the electroplating potential'must be in theelectrolyte, many difliculties have beenexperiencedin maintaining suitable electrical contact.

An important object of "the present invention is the provision of an efficient electrical connection between".submerged."soluble anodes and a source of electroplating current.

A iurtherimportant object of.v the present. invention is the provision of .aneificient electrical connection between movable soluble anodes submerged'in electrolyte andia source-of electroplating current. v H

A further important object of the present invention is the provision of;an improvedanode support for supplying electroplating current to movable soluble anodesiwhicmare submerged in electrolyte.

Other objects of the invention will become apparent from the following detailed description taken in connection with the accomp y n 2 drawings which disclose; apparatus incorporating the presentinvention.

Figure 1 is. a plan view of'an electroplating celliincorporating the present invention, the strip to be plated being omitted;

Figure 2 isaanenlarged viewin'sideelevation of the: embodiment of the present inventionshown in'Figure 1; and,

Figure? is an enlarged view in cross section taken ontheline3"-3oiFigure 2.

Referring to Figure 1, anelectroplating' cell is shown whi'ch may be ef the type more specifically disclosed in Patent No; 2,399,254; referred to above. Briefly, this cell embodies a trayindicated generally at'lU having'a pair of partitions H and IZdefinin'g a pair of overflow troughs l3and M and an electroplating cell l5 which is normally filled with an electrolyte (not shown) with which i the strip to be plated'makes contact. End walls [6 and ll of the tray are of the same height as partitions II and [2 so that electrolyte pumped into cell l5 will overflow all' the-walls when the tray is level. It will'be apparent that thestrlp can move through this cell with troughs l3 and I4 disposed on either side of the moving strip, or a pair of stripsmoving side by side'couldpass through the cell parallel to end members is and I1. The path of movement of the strip relative t'o the anodesis no'partof the present invention.

Considering the strip as moving through the cell with troughs l'r3-i' and" I4 disposed on either sideofzth'e" moving strip it will beapparent that cell" IEc isidivi'dedf by" an anode guide or support indicated'generally atv l8r'xtending transversely tothe'path' of'thez'stripl" Member Hi includesa guide.portionll'fiforming a pair of shoulders 20 and 2:! which slidablyreceive the ends of anode element's 22; A'sBl'isO'f anode elements 22 make up the pair ofanodes indicated generally at 23 and" 24'; Extendingparallelto'member lfi area pair 0f guide members 25 and 26 which support the' other endsoftheanod elements 22. Shoul ders 2n and 2| of member IB and the upper sur= facesof guidemembers or'ano'de supports 25 and are-inclined upwardly from'the trough'l l side ofthe. 0611150 that fresh-anode elements can be periodically inserted at the lower end and erodd ano'dei elements a withdrawn at the upper end of the incline tozm'ake'possible continuous replace ment ofithe'anodel Althoughthe anode support member: l'8=' isishown and described in 1 this bodimentit isi'to be understood! that thinvent'ioii is readily applicable to any electroplating bath in which the anode elements are fed electroplating current from a submerged contact member.

bus bar connection 29 which will generally be,"

formed of copper bars. These bars may be extended through most of the structure soas to be embedded in the extension 28 and in the base portion 2! as at 30 to offset the lower conductivity of the carbon.

Where deemed necessaryan eroded anode rest 36 may be provided on the outer end of base 21 to receive the end of an eroded anode element ejected from the anode.

Anode contact member 3! is molded or formed in any suitable maner to give a hard carbon surface for engagement with the anode, which surface shall be a good conductor of electricity and have good wear resistant characteristics. Since the surface is continuous the anodes may be moved therealong withelectrical contact being maintained.

In order to prevent the electrolyte from attacking base portion 2! a protective coating such as a rubber base paint is applied at 31. This protective coating may cover all the parts of the support below the liquid level of the electrolyte except for shoulders 29 and 2|. Although not essential it is an advantage to cover the exposed surfaces with this protective coating to reduce to a minimum evolution of gas at the carbon surface. Due to theconditions present, anode support I B will act as'an insoluble anode and there will be some evoluton of gas wherever the electrolyte contacts the carbon surface. Only shoulders 29 and 2| essential as contact surfaces need be left exposed.

I claim:

1. Apparatus for continuously electroplating the bottom surface of a moving strip of conductive material with a layer of protective metal comprising a horizontally disposed tray presenting an electroplating cell adapted to have the strip move along a path across the cell from end to end with the bottom surface in contact with electroplating solution in the cell, an anode support in the cell in position to be submerged in the electroplating solution below the bottom surface of the strip, the anode support including a member of molded carbon resistant to attack by the electroplating solution, the member of molded carbon having a base portion and a guide portion extending along the base portion and extending upwardly from the base portion, the base portion presenting surfaces exposed to the electroplating solution extending across the path of the strip and along opposite sides of the guide portion, a series' of soluble anode elements of protective metal slidably mounted on and in electrical contact with each'of the exposed inclined surfaces, each of the series of anode elements being slidable along and upthe respective inclined surfaces while maintaining electrical contact therewith, the carbon member including an extension portion extending upwardly from an end of the base portion and extending above the electroplating solution and the path of the strip, and electrically conductive metal embedded in the carbon 4 member, the metal including a first portion embedded in the base portion extending along and below the inclined surfaces for supplying electrical current to the surfaces and to the anode elements positioned on the surfaces and including a second portion embedded in the extension portion of the carbon member and extending upwardly outside of the extension portion of the carbon member for connection to a source of electroplating current, and a protective covering on the base portion preventing electrical contact of the electroplating solution with the surfaces of the base portion exposed to the electroplating solution except the inclined surfaces which are in electrical contact with the anode elements.

2. Apparatus for continuously electroplating the bottom surface of a moving strip of conductive material with a layer of protective metal comprising a horizontally disposed tray presenting an electroplating cell adapted to have the strip move along a path across the cell from end to end with the bottom surface in contact with electroplating solution in the cell, an anode support in the cell in position to be submerged in the electroplating solution below the bottom surface of the strip, the anode support including a molded carbon member resistant to attack by the electroplating solution, the molded carbon member having a base portion presenting a surface exposed to the electroplating solution, the exposed surface being inclined and extending across beneath the path of the strip, a series of soluble anode elements of protective metal slideably mounted on and in electrical contact with the exposed inclined carbon surface, the series of anode elements being slideable along and up the inclined surface while maintaining electrical contact therewith, the carbon member. including an extension portion extending upwardly from an end of the base portion and extending above the electroplating solution and the path of the strip, and an electrically conductive metal member embedded in the carbon member, the metal member including a first portion embedded in the base portion of the carbon member and extending beneath the inclined surface for supplying electric current to the surface and to the anode elements positioned along the surface and including a second portion embedded in the extension portion of the carbon member and extending upwardly outside of the extension portion of the carbon member for connection to a source of electroplating current.

WALTER W. KOMPART.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 7 

1. APPARATUS FOR CONTINUOUSLY ELECTROPLATING THE BOTTOM SURFACE OF A MOVING STRIP OF CONDUCTIVE MATERIAL WITH A LAYER OF PROTECTIVE METAL COMPRISING A HORIZONTALLY DISPOSED TRAY PRESENTING AN ELECTROPLATING CELL ADAPTED TO HAVE THE STRIP MOVE ALONG A PATH ACROSS THE CELL FROM END TO END WITH THE BOTTOM SURFACE IN CONTACT WITH ELECTROPLATING SOLUTION IN THE CELL, AN ANODE SUPPORT IN THE CELL IN POSITION TO BE SUBMERGED IN THE ELECTROPLATING SOLUTION BELOW THE BOTTOM SURFACE OF THE STRIP, THE ANODE SUPPORT INCLUDING A MEMBER OF MOLDED CARBON RESISTANT TO ATTACK BY THE ELECTROPLATING SOLUTION, THE MEMBER OF MOLDED CARBON HAVING A BASE PORTION AND A GUIDE PORTION EXTENDING ALONG THE BASE PORTION AND EXTENDING UPWARDLY FROM THE BASE PORTION, THE BASE PORTION PRESENTING SURFACES EXPOSED TO THE ELECTROPLATING SOLUTION EXTENDING ACROSS THE PATH OF THE STRIP AND ALONG OPPOSITE SIDED OF THE GUIDE PORTION, A SERIES OF SOLUBLE ANODE ELEMENTS OF PROTECTIVE METAL SLIDABLY MOUNTED ON AND IN ELECTRICAL CONTACT WITH EACH OF THE EXPOSED INCLINED SURFACES, EACH OF THE SERIES OF ANODE ELEMENTS BEING SLIDABLE ALONG AND UP THE RESPECTIVE INCLINED SURFACES WHILE MAINTAINING ELECTRICAL CONTACT THEREWITH, THE CARBON MEMBER INCLUDING AN EXTENSION PORTION EXTENDING UPWARDLY FROM AN END OF THE BASE PORTION AND EXTENDING ABOVE THE ELECTROPLATING SOLUTION AND THE PATH OF THE STRIP, AND ELECTRI- 